Identification key
The earliest examples of identification keys originate in the seventeenth, but their conceptual history can be traced back to antiquity.
The seventeenth-century Chinese herbalist, Pao Shan, in his treatise Yeh-ts'ai Po-Iu, included a systematic categorization of plants based on their apparent characteristics specifically for the purposes of identification.
[1]: 2 Seventeenth-century naturalists, including John Ray, Rivinius, and Nehemiah Grew, published examples of bracketed tables.
Identification keys are used in systematic biology and taxonomy to identify the genus or species of a specimen organism from a set of known taxa.
[1]: 14–15 Similar methods have also been used in computer science[7] A user of a key selects from a series of choices, representing mutually exclusive features of the specimen, with the aim to arrive at the sole remaining identity from the group of taxa.
In contrast, an artificial identification key is a tool that utilizes characters that are the easiest to observe and most practical for arriving at an identity.
In the nested style (also referred to as closed, yoked, and indented[9]: 63 ), the subsequent steps after choosing a lead are printed directly underneath it, in succession.
[9]: 61 An early attempt to standardize the construction of keys was offered by E. B. Williamson in the June 1922 volume of Science.
[10] More recently, Richard Pankhurst published a guidelines and practical tips for key construction in a section of his 1978 book, Biological Identification.
[2]: 15–22 Identification errors may have serious consequences in both pure and applied disciplines, including ecology, medical diagnosis, pest control, forensics, etc.
Text taken from Types of identification keys, Gregor Hagedorn, Gerhard Rambold, Stefano Martellos, Edizioni Università di Trieste.
